Saving Energy, One Bit at a Time

Its #EarthHour tonight which made me think of energy efficiency. Plants are very energy intensive so small energy efficiency improvements of just a few percent in a plant reduces energy consumption and carbon footprint more than heaps of individuals can. Moreover, plants can save lots of money by reducing their energy consumption. By quickly replacing steam traps as they fail, overhauling relief valves when they start passing, cleaning heat exchangers when they are fouling, lowering fan speeds when there is excess cooling, turning off equipment not in use, shutting off utilities not needed, fixing pipe and flange leaks, and other measures when equipment performance is degrading, plants can dramatically reduce their spending on energy. However, there are thousands of steam traps, hundreds of relief valves, hundreds of heat exchangers, tens of cooling tower and air cooled heat exchanger cells, hundreds of motors, thousands of valves, thousands of flanges and kilometers of pipe, and lots of boilers and fired heaters in a plant. It is not practical check all of this manually in a timely manner to maximize the efficiency and savings. Can automation help? What about IIoT? Here are my personal thoughts:

Plants around the world are reducing their energy consumption by deploying a second layer of automation to automate the data collection around the plant. By automatically monitoring energy consumption condition and efficiency in real time plants detect overconsumption, failures, and inefficiency in minutes. By taking remedial action much sooner these plants not only reduce their energy consumption but also save lots of time and money by not sending personal to inspect, clean, and overhaul equipment which are working fine and performing well.

This second layer of automation can in an existing plant be deployed without changing the control system. Old plants are being modernized using digital WirelessHART sensors. In modern plants based on Fieldbus, additional devices required for monitoring are simply added to the existing Fieldbus networks since they are usually not fully loaded. 

Apart from the additional sensors, analytics software is also important for monitoring steam trap failure, heat exchanger fouling, and excesses fan speed. 

Energy efficiency applications include:

Steam Trap Failure: steam traps blowing steam or trapping condensate are detected automatically within minutes, and replaced stopping energy waste and inefficiency. Time is not wasted checking steam traps which are working properly. A chemical plant in Singapore reduced its steam consumption by 7% thanks to Industrial Internet of Things (IIoT) with a new Data-as-a-Service (DaaS) business model outsourcing the steam trap monitoring.

Relief Valve Seat Passing: relief valve and other valves not seating properly therefore passing product to vent or flare are instantly detected, and overhauled stopping loss. Time is not wasted checking on relief valves which are not passing.

Relief Valve Release: relief valves simmering or releasing to flare or vent are detected and correlated to process conditions to tune the process to avoid reoccurrence. Time is not wasted on trying to interpret pressure trends to detect releases.

Heat Exchanger Fouling: excessive fouling is detected and pinpointed down to specific bundle, and cleaned to improve efficiency. Time is not wasted cleaning heat exchanger bundles which are operating efficiently.

Cooling Tower Excess Cooling: excessive cooling is detected and proper fan speed is suggested to reduce fan power while ensuring sufficient cooling capacity.

Air Cooled Heat Exchanger Fouling and Excess Cooling: excessive fouling is detected and pinpointed down to specific cell, and cleaned to improve efficiency. Time is not wasted on equipment operating efficiently. Excessive cooling is detected and proper fan speed is suggested to reduce fan power while ensuring sufficient cooling capacity.

Energy Management: all energy streams including water, air, gas, electricity, and steam (W.A.G.E.S) as well as other sources are monitored with finer granularity and compared to production rate to pinpoint overconsumption down to specific plant unit or equipment as per ISO 50001. This allows fast troubleshooting of overconsumption.

The same wireless and Fieldbus networks can also be used to improve reliability, HS&E, and productivity. See further explanation of these applications in this article:

https://www.ceasiamag.com/2015/08/plant-modernization-for-energy-efficiency-and-loss-control/

Well, that’s my personal opinion. If you are interested in how the digital ecosystem is transforming process automation click “Follow” by my photo. Click “Like” if you found this useful to you and share it with others if you think it would be useful to them.